Smart batteries may be provided with at least one extra terminal (contact) for a communication interface that may be used to communicate, for example, with a digital processor that stores battery information used to adjust charging parameters for that battery. However, not all battery powered applications allow adding an additional terminal to the battery because such an additional terminal(s) is not always possible given a desired mechanical configuration for the battery. Currently available solutions are all direct current (DC) based, using changes in the battery voltage and/or battery load to transmit data to an external receiving device. To modulate the impedance of the battery requires a high current device in series with the battery and may possibly interfere with battery charging operations. Adding an additional terminal to the battery requires modification to the battery mechanics and requires modification to the battery holder mechanics which is undesirable.